The SitePoint PHP blog has posted a tutorial from Christopher Pitt with another interesting use of PHP: using it and React to scan fingerprints to aid in multi-factor authentication.

We live in interesting times. A short while ago, a company called OfferZen announced a new, programmable credit card. It’s been a long time since I was this excited to get my hands on a piece of tech. My mind has been brimming with ideas ever since.

So, I decided to write about one of them!

I’m going to describe the process of building custom multi-factor authentication for all transactions. I don’t want to do the usual (and boring on its own) SMS or push notification one-time-password stuff. I want to build a fingerprint scanner right into my phone. [...] In this tutorial, we’re going to look at how to set up a simple iOS app using React Native. We will also set up an asynchronous HTTP server, with a web socket connection to the app.

He starts by taking some time to introduce React Native for those not familiar with it and what it brings to the table. He then walks through the installation of React Native and how to install the TouchID package using yarn. He also includes some simple JS code you can use to ensure it's all working. Next up he uses PHP to create an asynchronous server with the amphp/aerys package (this code). He creates the server with a "scan" endpoint handlers for opening the connection, performing the handshake and reacting to incoming data. Then he brings them together, connecting React and PHP, and sets up a script to wait for fingerprints. Code is included to perform the validation of the fingerprint and the end result should look something like this.